FNR 24150 Herps Exam 1

Gymnophiona

Caecilians

- Burrowing lifestyle, some fully aquatic

- Annulated and has wedge shaped skull

- Vestigial eyes, acute olfactory system

- Internal fertilization, all reproductive stages present

- Retractable sensory tentacles, special feeding mechanism

Caudata

Salamanders

- Mostly northern hemisphere (cooler habitats)

- 10 recognized families, 68 genera, ~800 species

- Smooth skin and long cylindrical bodies

- Short limbs, some no hind limbs

- Costal grooves

- Five toes on hind limbs, four toes on front limb

- Some aquatic, terrestrial, fossorial, or even arboreal

- Nocturnal/crepuscular

- Fossorial and secretive

- Mostly internal fertilization (except two families)

- Carnivorous

Sirenidae

Sirens

-External fertilization (predicted, but unconfirmed)

- Most primitive (No hind limbs, fully aquatic, paedomorphic)

- Lives in swamps, and even roadside ditches

- Aestivation: Mucous membrane to prevent drying out

Mostly nocturnal

- Hard to observe, Eastern North America

Cryptobranchidae

Hellbenders and Giant Salamanders

- External fertilization

- Long lives and older maturity age (7 years)

- Paedomorphic

- Lateral skin folds for cutaneous respiration

- Really small, mostly non-functional lungs

- Live in cold, fast flowing streams and hide under rocks

- Males super territorial of nests under rocks

- Females come to nest and lay eggs, males externally fertilize them

Plethodontidae

Lungless salamanders

- Largest group

- Nasolabial groove

-No lungs, just cutaneous respiration

-No gills, dependent on moist environments

- Prominent costal grooves

- Most are terrestrial, some fully aquatic or arboreal

- Diverse reproductive modes (aquatic larvae with metamorphosis, egg hatching into miniature adults with no external gills, etc.)

Proteidae

Mudpuppies

- Deep, clear lakes

- Have hindlimbs unlike sirens

- Paedomorphic, fully aquatic

- Internal fertilization, eggs attached to roof of burrow

- Unclear whether intentionally defended by female, but eggs protected by her presence

- Conservation concern because of water quality

Salamandridae

True Salamanders and Newts

- Relatively small

- Lack gills and gill slits usually, present fuctional lungs

- Internal fertilization

Thick granular skin, numerous poison glandsm aposematic coloration

- Courtship displays, internal fertilization

- Carnivorous

Ambystomatidae

Mole Salamanders

- Fossorial

- Stout bodies, thick limbs and tails, short blunt heads

- Costal grooves

- Adults terrestrial, lay eggs in water and they metamorphose

- Tiger salamanders can be neotenic (axolotl part of tiger salamanders)

- Some dont lay eggs in water (lay on land and wait for water inundation)

- Aggregate or explosive breeders (First warm, strong rain, males first then females, males lay spermatophores)

Anura

Frogs and toads

- Most diverse amphibians (57 families, 468 genera, ~7700 genera)

- Moist tropics mostly, large global distribution, cannot adapt to salt water

- Dorsolateral folds in some frogs

- Cranial crests and parotid glands in some toads

- Tympanum size

Size or presence of toad pads

- Movement strategy (jumping/hopping, walking, climbing, fully aquatic swimmers)

- Vocalizations (advertisement, aggresive, courtship, release, alarm or defense)

Leiopelmatidae

Tailed Frogs and New Zealand Frogs

- Five species of tailed frogs

- Tail-like structure for copulation ("tail" is actually highly vascularized extension of cloaca)

Scaphiopodidae

Spadefoot toads

Hylidae

Tree frogs

Centrolenidae

Glass Frogs

Bufonidae

True toads

Ranidae

True Frogs

Dendrobatidae

Poison dart frogs

Crocodilia

Crocodiles and alligators

- Only remaining archosaurs

- 150 recognized species

- Armored, thick plated skin

- Largest living reptile

- Elongated head, string tooth jaws, short and strong limbs

- Nests on land (amniotic egg)

- Temperature-dependent sex characteristics

Rhynchocephalia/Sphenodontidae

Tuataras

Testudines

Turtles and tortoises

- Shelled reptiles

- Ribs and vertebrae fused to form shell

- Upper is carapace, lower is plastron

- Diverse order and relatively species-rich

- Some fully aquatic, some fully terrestrial, some marine, some freshwater

- Highly diverse in size

- Flexible necks with 8 cervical vertebrae

Trionychidae

Soft shelled turtles

Cheloniidae

Sea turtles

Chelydridae

Snapping turtles

Kinosternidae

Mud and musk turtles

Emydidae

Pond and Box Turtles

Testudinidae

Tortoises

Squamata

Lizards and snakes

Amphisbaenia

worm lizards

Gekkonidae

Geckos

Phrynosomatidae

Spiny lizards

Anguidae

Glass lizards and alligator lizard

Helodermatidae

Gila monster and Mexican beaded lizard

Teiidae

whiptails

Scincidae

Skinks

Serpentes

snakes

Viperidae

vipers and pit vipers

Pythonidae

Pythons

Elapidae

coral snakes

Colubridae

Colubrids

Natricidae

water snakes

Dipsadidae

rear-fanged snakes

Eft stage

Stage in a salamander's life that allows them to stay in dry environments until sexual maturity, can be in this stage for 2-3 years

Unken Reflex

- Aposematic coloration

- Posturing behavior advertising toxicity to predators

- Used for chemical defense

- Used by many amphibians

Frogs vs toads

Toads have rough, warty skin and shorter hind-limbs for hopping. They are also more tied to land.

Frogs have smoother skin, longer legs for leaping, and are more tied to water

Which era is called the Age of Reptiles?

Mesozoic Era

Diapsids

Archosaurians and lepidosaurs

- Larger, stronger jaw muscles

Anapsids

Primitive group with no temporal fenestrae

Synapsids

Mammals and mammal-like reptiles

- Possess single large fenestrae

Amniotes

Small-lizard like animals

- Salamander-like and had the first amniotic egg

Hylonomus

Possibly the earliest known reptile

- Distinct scale marks, sharp teeth and insectivorous

- Anapsid morphology

Archosauromorphs

First major diapsid lineage

- Gave rise to crocodilians and birds (and potentially turtles)

Crocodilians

Surviving archosaurs

- Early ancestors lived in Jurassic to mid-Cretaceous

Lepidosauromorphs

2nd major diapsid lineage

- Lizards, snakes, tuataras

- Appeared in late Permian

Megachirella

Oldest lepidosaur fossil that lived in Triassic

Tuatara

Living fossils

- Descended from rhynchocephalia

- Late Triassic to Mesozoic

- One species exists today, endemic to New Zealand

Turtles: Anapsid vs Diapsid

- Often considered surviving anapsids, but modern study suggests they're diapsids

- Have no tmeporal fenestrae but some fossils have small ones

Odontochelys

- Toothed turtle in late triassic

- Toothy protrusions on shell

- Incomplete carapace

Proganochelys

- Contains few teeth in beak

- Shell more similar to modern turtles

Eileanchelys

Earliest pond turtle

- Contains characteristics of modern-day turtles

Archelon

- Largest turtle on record

- Leathery shell and large flipper-like limbs

- Leatherback is closest living relative

Alligators vs. Crocodiles

Alligators have no lingual salt glands, but crocodiles do